Pesticides are chemicals widely used
for agricultural industry,
despite their negative impact on health and environment. Although
various methods have been developed for pesticide degradation to remedy
such adverse effects, conventional materials often take hours to days
for complete decomposition and are difficult to recycle. Here, we
demonstrate the rapid degradation of organophosphate pesticides with
a Zr-based metal–organic framework (MOF), showing complete
degradation within 15 min. MOFs with different active site structures
(Zr node connectivity and geometry) were compared, and a porphyrin-based
MOF with six-connected Zr nodes showed remarkable degradation efficiency
with half-lives of a few minutes. Such a high efficiency was further
confirmed in a simple flow system for several cycles. This study reveals
that MOFs can be highly potent heterogeneous catalysts for organophosphate
pesticide degradation, suggesting that coordination geometry of the
Zr node significantly influences the catalytic activity.
Increasing anthropogenic activities have adversely affected freshwater supply, making it an important global issue. Water resources are often contaminated by industrial dyes, which may harm both environment and human health even at low-level exposure. Herein, we report the adsorptive removal of a representative azo dye, methyl orange (MO) on PCN-224, a Zr porphyrinic metal−organic framework (MOF). Nanoporous PCN-224 has desirable structural characteristics such as an optimal pore aperture and a large pore volume optimized for trapping MO molecules, in addition to superior water stability. Significantly, through the combined investigation of experimental and theoretical studies, multiple adsorption sites such as the porphyrin linkers and Zr 6 nodes of the framework formed π−π interactions and hydrogen bonding with MO molecules, respectively, affording the highest adsorption capacity among the reported MOFs.
Quinolone-based antibiotics commonly
detected in surface, ground,
and drinking water are difficult to remove and therefore pose a threat
as organic contaminants of aqueous environment. We performed adsorptive
removal of quinolone antibiotics, nalidixic acid and ofloxacin, using
a zirconium–porphyrin-based metal–organic framework
(MOF), PCN-224. PCN-224 exhibits the highest adsorption capacities
for both nalidixic acid and ofloxacin among those reported for MOFs
to date. The accessible metal sites of Zr metal nodes are responsible
for efficient adsorptive removal. This study offers a pragmatic approach
to design MOFs optimized for adsorptive removal of antibiotics.
The data that supports the findings of this study are available in the supplementary material of this article. CCDC 2004846 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via https://www.ccdc.cam.ac.uk/data_request/cif.
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